判断客户端是否安装realplayer

<SCRIPT   language="javascript" type="text/javascript">  
        var   IsInstallRealPlayer;  
        var   IsInstallMediaPlayer;  
        IsInstallRealPlayer=false;  
        IsInstallMediaPlayer=false;  
      </SCRIPT>  
   
      <SCRIPT   type="text/vbscript">  
        On Error Resume Next  
        Set   f=CreateObject("rmocx.RealPlayer G2 Control.1")  
        IF   IsObject(f)   Then  
          IsInstallRealPlayer=True  
        End   If  
        Set   f=CreateObject("MediaPlayer.MediaPlayer.1")  
        IF   IsObject(f)   Then  
          IsInstallMediaPlayer=True  
        End   If  
      </SCRIPT>  
   
      <SCRIPT   language="javascript" type="text/javascript">  
        if(IsInstallRealPlayer==false)  
        {  
          alert("没有装入RealPlayer");
          window.location.href="http://cn.real.com"; 
        }  
        if(IsInstallMediaPlayer==false)  
        {  
          alert("没有装入RealPlayer");
          window.location.href="http://cn.real.com";    
        }  
      </SCRIPT>